document.write( "Question 1195527: PQR is an isosceles triangle with a base of 18 cm and sides of 15 cm and is inscribed in a circle with its vertices touching the circumference of the circle. The radius, in centimetres, of the circle is? \n" ); document.write( "
Algebra.Com's Answer #828044 by ankor@dixie-net.com(22740)\"\" \"About 
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PQR is an isosceles triangle with a base of 18 cm and sides of 15 cm and is inscribed in a circle with its vertices touching the circumference of the circle. The radius, in centimetres, of the circle is?
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\n" ); document.write( "draw this out, assume the base of the triangle (18cm) is below the center
\n" ); document.write( "Find the height of the triangle using pythag;
\n" ); document.write( "h goes thru the center.
\n" ); document.write( "h = \"sqrt%2815%5E2+-+9%5E2%29\"
\n" ); document.write( "h = 12 cm
\n" ); document.write( ":
\n" ); document.write( "let x = dist from the center to the center of the base, then we have
\n" ); document.write( "r = 12 - x
\n" ); document.write( "drawn a right triangle using the radius (r), x and half the base (9), find r
\n" ); document.write( "r = \"sqrt%28x%5E2+%2B+9%5E2%29\"
\n" ); document.write( ":
\n" ); document.write( "r = r therefore
\n" ); document.write( "\"sqrt%28x%5E2%2B9%5E2%29\" = 12 - x
\n" ); document.write( "square both sides
\n" ); document.write( "\"x%5E2+%2B+9%5E2++=+144+-+24x+%2B+x%5E2\"
\n" ); document.write( "x^2 drops out
\n" ); document.write( "81 = 144 - 24x
\n" ); document.write( "24x = 144 - 81
\n" ); document.write( "24x = 63
\n" ); document.write( "x = 63/24
\n" ); document.write( "x = 2.625
\n" ); document.write( "find the radius
\n" ); document.write( "r = 12 - 2.625
\n" ); document.write( "r = 9.325
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